Reflex Sympathetic Dystrophy

Reflex sympathetic dystrophy (RSD) is a term commonly used to describe severe pain and burning in an upper or lower limb following injury.

Description

S.W. Mitchell in 1864 described this symptom complex in great detail and provided the designation of causalgia (from the Greek "kausis" - burning, and "algos" - pain.)

In 1947, it was argued that the causalgia and related syndromes were merely manifestations of one disease entity and the all-encompassing name of reflex sympathetic dystrophy was adopted. It is also known as algodystrophy, causalgia syndrome, post-traumatic dystrophy, reflex neurovascular dystrophy, and Steinbrocker syndrome.

Causes

The cause is unclear but a number of factors may contribute, particularly changes in autonomic nervous system function. RSD may be associated with crush injuries, fractures, infections, burns, radiation therapy, and myocardial infarction.

RSD appears to be more common among women than men, and among individuals over 50 years of age. It has also been seen among children and young adults.

Symptoms

The usual presenting symptom is burning pain and stiffness in an arm or leg (although any area of the body may be affected) at the site of a previous injury but extending beyond the area of the earlier injury. Pain severity may be worse than the original injury.

In the early stages, there may also be erythema, tenderness and swelling. Range of motion may be decreased. In some patients the condition progresses. Pain worsens, range of motion is further restricted, and weakness may be present. The skin may appear cool and clammy and may become glossy. The pain is often worse at night.

A further stage may be associated with a decrease in pain, although more commonly pain becomes intractable and only mild relief can be obtained with treatment. Severe tendon contractures and muscle atrophy may accompany loss of strength.

Diagnosis

Diagnosis is made based on the medical history and physical exam. X-rays of the affected limb may show osteopenia (bone loss).

Treatment

Although no standard treatment has been developed, prevention and early treatment of symptoms are recommended. Daily physical therapy should begin as soon as the diagnosis is confirmed. Whirlpool and paraffin wax baths are sometimes beneficial.

Ice or heat applications should be avoided in most cases because they seem to cause over stimulation of nerve endings, resulting in increased discomfort. Protecting the extremity from irritating stimuli is important.

If the conditions progresses, a widely employed therapeutic intervention for RSD has been cervical or lumbar paravertebral sympathetic blockade with the injection of anesthetics such as mepivacaine or bupivacaine. The pain relief may be dramatic, with a duration outlasting the action of the anesthetic.

Some patients may be cured by sympathectomy (a surgical procedure that involves excision of one or more sympathetic nerves). Transcutaneous electrical nerve stimulation (TENS) may be helpful, and a prolonged trial at multiple locations and stimulation parameters should be attempted.